Daniel Shilts Jr., who was arrested Feb. 20 after an explosion at his Waldo home, was charged Tuesday with 52 felonies related to the possession of improvised explosives.

Shilts, 42, was arrested for violating parole after chemicals used to make fireworks and explosives were found at his home.

Waldo explosion tied to man with bomb convictions

Shilts' bail was set at $75,000 for 51 charges of possession of improvised explosives and one charge of possession of explosive materials to make an improvised device, all felonies.

"To be fair to Mr. Shilts, I have prosecuted him twice for related matters," District Attorney Joe DeCecco said. "He has never threatened anyone. He has never harmed anyone, except himself I guess on occasion. He is not a member of any organization, we have vetted him since we began cases with him. He is simply obsessed, your honor, with explosives and the chemistry of explosives."

According to the criminal complaint:

Shilts was arrested Saturday, Feb. 20, after law enforcement was dispatched to his house for a report of an explosion. Upon arrival, officers found that 10 windows had been blown out of the home, and Shilts had blood on his pants leg and a cut on his left hand.

Shilts initially told officers that his windows had blown out from a "welding accident" involving a welding torch and an aerosol can, but judging by the damage to the home, officers believed that more than an aerosol can exploded.

Officers noticed what appeared to be explosive powder and explosive mortar shells similar to those used in fireworks displays and requested the Milwaukee County Bomb Squad search the residence.

The following morning, the bomb squad and agents from the Federal Bureau of Alcohol, Tobacco and Firearms searched the home and recovered more than 70 pounds of materials used for making improvised explosives — including sulfuric and boric acids, magnesium, potassium nitrate and potassium chlorate.

In addition, officers collected 51 improvised explosive devices, all of which were fashioned into firework shells.

If the original explosion would have set of the 51 explosive devices, or if a fire had set them off, "that residence would have been destroyed and the adjacent houses significantly damaged if not destroyed by the blast," according to the ATF.

“The devices located in his house on the date in question were powerful, they were homemade, allegedly, they were quite capable of causing death or great bodily harm, and even the law enforcement agencies present, such as the civil support team from the National Guard and the ATF, became quite concerned over the power of these explosives,” DeCecco said.

Shilts did not have a permit or license to manufacture or possess explosive devices, which is required under federal law.

Shilts has a history for possessing explosives and explosive-making materials. He was convicted in a 2008 case for possession of improvised explosive devices and was convicted of felony bail jumping in a 2012 case in which he was found with chemicals used to make fireworks.

Shilts was out on parole during the Feb. 20 incident with conditions that he not possess explosive materials.

“He was placed on probation for his first improvised explosive conviction. That got revoked and he was sent to prison," DeCecco said. “He has a tough time, in my opinion, following a simple provision of staying away from the stuff.”

When Shilts was first arrested for explosives in 2007, investigators found a collection of explosive chemicals — including sulfuric and nitric acids, glycerin, potassium nitrate and Pyrodex powder — as well as a handbook for explosive making.

Shilts told investigators at that time that he became interested in explosives about around 2006 and had put together three batches of nitroglycerin since then. Sheriff's officials at the time said he had an interest in chemistry and fireworks and did not seem intent on hurting anyone.